// Copyright 2015 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CONTENT_RENDERER_P2P_FILTERING_NETWORK_MANAGER_H_
#define CONTENT_RENDERER_P2P_FILTERING_NETWORK_MANAGER_H_

#include "base/macros.h"
#include "base/memory/weak_ptr.h"
#include "base/threading/thread_checker.h"
#include "base/time/time.h"
#include "content/common/content_export.h"
#include "content/renderer/p2p/network_manager_uma.h"
#include "third_party/webrtc/base/network.h"
#include "third_party/webrtc/base/sigslot.h"
#include "url/gurl.h"

namespace media {
class MediaPermission;
} // namespace media

namespace content {

// FilteringNetworkManager exposes rtc::NetworkManager to
// PeerConnectionDependencyFactory and wraps the IpcNetworkManager. It only
// handles the case where multiple_routes is requested. It checks at least one
// of mic/camera permissions is granted before allowing WebRTC to use the local
// IP addresses as ICE candidates. The class handles asynchronous signals like
// SignalNetworksChanged from IpcNetworkManager and permission status from
// MediaPermission before it signals WebRTC that the network information is
// ready. It is designed to fire the network change event at the earliest time
// to reduce any extra call setup delay. This class is not thread safe and
// should only be used by WebRTC's network thread. It inherits from
// rtc::NetworkManagerBase to have the same implementation of
// GetAnyAddressNetworks(). We can't mark the whole class CONTENT_EXPORT as it
// requires all super classes to be CONTENT_EXPORT as well.
class FilteringNetworkManager : public rtc::NetworkManagerBase,
                                public sigslot::has_slots<> {
public:
    // This class is created by WebRTC's signaling thread but used by WebRTC's
    // worker thread |task_runner|.
    CONTENT_EXPORT FilteringNetworkManager(
        rtc::NetworkManager* network_manager,
        const GURL& requesting_origin,
        media::MediaPermission* media_permission);

    CONTENT_EXPORT ~FilteringNetworkManager() override;

    // rtc::NetworkManager:
    void Initialize() override;
    void StartUpdating() override;
    void StopUpdating() override;
    void GetNetworks(NetworkList* networks) const override;
    bool GetDefaultLocalAddress(int family,
        rtc::IPAddress* ipaddress) const override;

private:
    // Check mic/camera permission.
    void CheckPermission();

    // Receive callback from MediaPermission when the permission status is
    // available.
    void OnPermissionStatus(bool granted);

    base::WeakPtr<FilteringNetworkManager> GetWeakPtr();

    // Receive callback from the wrapped NetworkManager when the underneath
    // network list is changed.
    void OnNetworksChanged();

    // Reporting the IPPermissionStatus and how long it takes to send
    // SignalNetworksChanged. |report_start_latency| is false when called by the
    // destructor to report no networks changed signal is ever fired and could
    // potentially be a bug.
    void ReportMetrics(bool report_start_latency);

    // A tri-state permission checking status. It starts with UNKNOWN and will
    // change to GRANTED if one of permissions is granted. Otherwise, DENIED will
    // be returned.
    IPPermissionStatus GetIPPermissionStatus() const;

    void FireEventIfStarted();

    void SendNetworksChangedSignal();

    // |network_manager_| is just a reference, owned by
    // PeerConnectionDependencyFactory.
    rtc::NetworkManager* network_manager_;

    // The class is created by the signaling thread but used by the worker thread.
    base::ThreadChecker thread_checker_;

    media::MediaPermission* media_permission_;

    int pending_permission_checks_ = 0;

    // Whether we're waiting for a network change signal from |network_manager_|.
    bool pending_network_update_ = false;

    // Whether we have fired the first SignalNetworksChanged.
    // Used to ensure we only report metrics once.
    bool sent_first_update_ = false;

    // SignalNetworksChanged will only be fired if there is any outstanding
    // StartUpdating.
    int start_count_ = 0;

    // Track whether CheckPermission has been called before StartUpdating.
    bool started_permission_check_ = false;

    // Track how long it takes for client to receive SignalNetworksChanged. This
    // helps to identify if the signal is delayed by permission check and increase
    // the setup time.
    base::TimeTicks start_updating_time_;

    GURL requesting_origin_;

    base::WeakPtrFactory<FilteringNetworkManager> weak_ptr_factory_;

    DISALLOW_COPY_AND_ASSIGN(FilteringNetworkManager);
};

} // namespace content

#endif // CONTENT_RENDERER_P2P_FILTERING_NETWORK_MANAGER_H_
